For nearly seven years, Republicans have run — and won — on the campaign promise to get rid of the 2010 health care law.

But now that House Republicans are on record on their own replacement plan, that unifying offensive message has faded, especially since some of their most vulnerable incumbents are at odds with leadership and the White House on what’s being touted as the party’s first major legislative victory this Congress.

Not all districts are created equal. They all count the same when adding for a majority, but victories in one type of district may portend a much better night for Democrats than in others. With just four days to go until Election Day, Democrats almost surely won’t gain the 30 seats needed for a House majority on Tuesday. But they will make some gains. Here’s where to watch for early clues as to just how big or small Democratic gains will be.

To achieve double-digit gains, Democrats must win the known battlegrounds. These are the districts that always were going to be competitive, and where presidential year turnout usually gives Democrats an advantage. At the very least, Democrats need to win the districts that President Barack Obama carried — places like Illinois’ 10th District, Nevada’s 4th and 3rd Districts, Maine’s 2nd District, Florida’s 26th District, (which is now even more Democratic), Iowa’s 1st District and New York’s 19th District. If they’re not able to win these seats, Democratic gains in the House will likely be very minimal.

Now the super PAC aligned with Hillary Clinton’s presidential campaign is setting its sights on the Republican freshman in its first foray into a House race, The Washington Post’s Paul Kane first reported Wednesday morning.

The good news for Republicans is that the bottom hasn’t fallen out from underneath their down-ballot candidates. The bad news is that there are still nearly three weeks left before Election Day, and 24 hours in each day for Donald Trump to torpedo the party’s chances of holding the House.

District-level polling after the release of the 2005 “Access Hollywood” video and the second debate between Trump and Hillary Clinton showed some vulnerability for Republicans, particularly in suburban districts. But we didn’t see a widespread cratering of GOP candidates in the competitive districts or evidence that the number of competitive seats is increasing dramatically.